Record gold prices and a government crackdown on cocaine trafficking have prompted the leftist Revolutionary Armed Forces of Colombia (FARC) and new criminal gangs linked to former far-right paramilitaries to seek new revenue sources and expand into illegal mining in recent years, the police say.

National police chief Rodolfo Palomino has said armed groups are using increasing amounts of mercury, cyanide and arsenic to extract gold in the remote western jungle province of Choco along the Pacific coast. Five grams of mercury are needed to extract one gram of gold, he said.

“Water sources have been diverted and contaminated by the dumping of tonnes of chemicals,” Palomino told reporters recently, adding that 4,000 hectares of rainforest in Choco have been cut down to make way for illegal mining.

Police say that illegal gold mining can yield profits five times greater than returns from cocaine, and that the FARC and other armed groups are known to extort money from regular miners as well as operating their own illegal mines.

The environmental damage, in the form of razed tropical rainforest and extinction of native fauna, caused by illegal gold mining and mercury use is set to rise because FARC rebels and a powerful criminal gang known as the Urabenos, who operate on the Pacific coast, recently joined forces, Palomino said.

TOXIC MERCURY

For centuries miners have used mercury to separate gold from rock or soil. Mercury dissolves to form an amalgam with gold, and when boiled this leaves behind a solid gold nugget and fumes which can cause mercury poisoning if inhaled.

Mercury seeps into soil, rivers and the food chain and can cause serious health problems which may not appear for years, according to the United Nations Environment Programme (UNEP).

“Mercury remains a major global, regional and national challenge in terms of threats to human health and the environment, especially but not uniquely to the health of pregnant woman and babies worldwide through the eating of contaminated fish,” a 2013 UNEP report said.

Colombia ranks among the world’s top 20 gold producers, and is one of the world's leading per capita emitters of mercury, largely because of gold mining, the United Nations says.

Worldwide, around 15 million people - from Colombia, Indonesia and Peru to Ghana – are thought to earn a living from small-scale gold mining, and most use mercury to extract the precious metal from rock.

Colombia's Choco and northwestern Antioquia provinces, both rich in silver and gold reserves, have become centres of both legal and illegal mining in the past seven years, police authorities say.

In both provinces, thousands of poor families, driven from their homes by warring factions during Colombia’s 50-year internal conflict, pan for scraps of gold in muddy rivers, while Brazilian dredges work non-stop to dig up river sediment in the search for gold.

CLOSING ILLEGAL MINES

About half of all mining operations in Colombia are illegal, the authorities say.

The government says it is clamping down on illegal mining and is shutting down hundreds of mines operating without a government licence every year. Army helicopters and rural police patrol remote jungle areas targeting illegal mines run by organised crime networks.

So far this year, Colombian police say they have seized 48 illegal mines, destroyed 129 bulldozers and charged 308 people with illegal mining.

Rights groups and indigenous tribes in Choco province say the government has been too slow to react to the armed groups’ intrusion on the mining boom and that as soon as illegal mines are shut down, new ones spring up within weeks.

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